- Commas are used to separate groups of words that belong together from other groups that belong together. If you set off one group of words from another, your reader will not accidentally run them together and get confused.
- Use a comma after an introductory element in a sentence.
Example When the Broncos won the game, the crowd went wild.
Example George, do you want to play some basketball?
- Use two commas, one at the beginning and one at the end, to set off interrupting elements.
Example Ms. Wingfield, my freshman seminar teacher, helped me pre-register.
Example Use two colors, one on each side, when you make the banners.
NOTE: If the interrupting element is an essential part of the sentence--if the basic meaning of the sentence changes without that part-- it doesn’t take a comma. Because the element is part of the larger group of words, it shouldn’t be separated out.
Example All drivers who are under 25 have to pay higher insurance. (If you leave out who are under 25, the sentence meaning changes, so the element is essential and shouldn’t be separated out. No comma is needed.)
Example Chancellor McLeod, who loves FSU, attended school here as a student. (If you leave out who loves FSU the main sentence is left intact, so the element is not essential. You should separate it with commas on either side.)
- Use a comma to separate afterthoughts.
Example We must look at all rappers, not just Eminem.
Example Please shut the door, Andy.
Example We will practice, which will help us win.
- Commas are used to separate items in a series, whether they are words, phrases, or clauses.
Example I brought a pen, paper, and books to class.
Example We will go to the store, do some jogging, and go home.
- Commas are used when joining two sentences with a coordinate conjunction (FAN BOYS word--for, and, nor, but, or yet, so).
Example She wanted new Nikes, but he preferred the Reeboks.
Example She doesn’t have money for the shoes, so she has to get a job.
- Commas are used in standard places.
- Between city and state
Example Fayetteville, NC
- Between the date and year
Example January 1, 2000
- After the closing in any letter
Example Sincerely, John
- After the opening in a personal letter
Example Dear Mom and Dad,
- In numbers
Do not use a comma unless you have a reason. When in doubt, leave it out.